This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-156550, Jun. 3, 1999, the entire contents of which is incorporated herein by reference.
The present invention relates to an electronic still camera, and particularly to a camera shake proof electronic still camera being adapted to detect camera shake and to start an exposure operation at the timing of the camera shake becoming small.
In Jpn. Pat. Appln. KOKAI Publication No. 10-48681, a silver salt camera is disclosed which is adapted to monitor camera shake conditions after the release operation and to start film exposure when the quantity of camera shake has dropped below a predetermined value.
Further, in Jpn. Pat. Appln. KOKAI Publication No. 8-256289, a digital camera estimating the release time at which the result of shake detection falls within a predetermined permissible value and generating an image acquisition signal is disclosed.
However, since accidental camera shakes have no regularity, it is difficult to estimate them, and due to such error factors as response delay of a mechanical shutter, start delay of integration control of an imaging element or the like, a method of estimating camera shake conditions can not always produce a satisfactory result.
Therefore, the object of the present invention is to provide an electronic still camera having an improved camera shake preventing performance without estimating future camera shake conditions and without involving an increase in cost or size.
In order to attain said object, an electronic still camera according to a first aspect of the present invention comprises:
an imaging device imaging an object;
a release section putting an imaging operation of said imaging device into effect;
a camera shake detection circuit detecting the quantity of camera shake during the imaging operation of said imaging device; and
a sequence control circuit evaluating the quantity of camera shake during the imaging operation detected by said camera shake detection circuit in response to a release operation by said release section and reading out an imaging signal when the result of camera shake detection is below a predetermined value.
Further, an electronic still camera according to a second aspect of the present invention comprises:
an imaging control circuit capable of repeating an imaging operation by an imaging device in response to a release operation;
a camera shake detection circuit detecting camera shake conditions in parallel with said imaging operation; and
a sequence control circuit evaluating the quantity of camera shake at a predetermined time of imaging operation by the imaging device, instructing the next imaging operation when the quantity of camera shake is below a predetermined value and terminating the imaging operation in order to read out picture data when the quantity of camera shake is below the predetermined value.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.